Overbased calcium salts of alkenylsuccinimide

ABSTRACT

WHERE R is H, CH3 and/or C2H5 and x is from 0.5 to 1.5 at a temperature of between about 50* and 180*C. in the presence of water and preferably in the presence of an inert liquid diluent.   WHERE R&#39;&#39; is as heretofore defined with a CO2 blown calcium 2alkoxyalkoxide complex characterized by the formula:   WHERE R&#39;&#39; is alkenyl of from 30 to 300 carbons and y is an integer of from about 0.1 to 18, said overbased calcium salt prepared by contacting alkenylsuccinimide of the formula:   An improved dispersant and rust inhibiting additive for automotive lubricating oils comprising overbased calcium salt of alkenylsuccinimide characterized by the formula:

tates Hellmuth et a1.

atet 1 Oct. 9, 1973 OVERBASED CALCIUM SALTS OF ALKENYLSUCCINIMIDE [75]Inventors: Walter W. Hellmuth, Beacon; Elmer E. Schallenberg, Fishkill,both of [73] Assignee: Texaco Inc., New York, NY.

[22] Filed: Oct. 14, 1971 [21] App]. No.: 189,370

Primary Examiner-Daniel E. Wyman Assistant Examiner-H. M. S. SneedAttorney-Thomas H. Whaley et al.

[57] ABSTRACT An improved dispersant and rust inhibiting additive forautomotive lubricating oils comprising overbased calcium salt ofalkenylsuccinimide characterized by the formula:

N Ca-yCaCO where R is alkenyl of from 30 to 300 carbons and y is aninteger of from about 0.1 to 18, said overbased calcium salt prepared bycontacting alkenylsuccinimide of the formula:

where R is as heretofore defined with a C0 blown calcium2-alkoxyalkoxide complex characterized by the formula:

where R is H, CH and/or C 11 and x is from 0.5 to 1.5 at a temperatureof between about 50 and 180C. in the presence of water and preferably inthe presence of an inert liquid diluent.

9 Claims, No Drawings OVERBASED CALCIUM SALTS OF ALKENYLSUCCINIMIDEBACKGROUND OF INVENTION Mineral lubricating oil employed as crankcaselubricants in internal combustion engines tend to oxidize at the hightemperatures to which they are subjected in this type of service withthe resultant formation of gums, sludges which clog the oil feed linesand form varnish-like deposits on the surfaces of rings, pistons,cylinders and other engine parts. Further, with emission control devicesbeing installed on the presently manufactured automotive vehicles, muchof the corrosive bodies of the engine exhuast system are not 7introduced into the crankcase oil. The gums and sludges lead to pistonsticking and varnish on the cylinder walls. This coupled with the attackof the corrosive bodies on the engine metal surfaces cause substantialdeterioration of the engine operation.

In order to counteract these negative factors, additives are added tocrankcase oils in small amounts such as dispersants to counteract theformation of gums and sludges and anticorrosives to inhibit thecorrosive action of the exhaust gases introduced into the crankcasesystem. One of the suitable known dispersants are the normal metal saltderivatives of the alkenylsuccinimide where the alkenyl portion rangesfrom 15 to 30 carbons as represented in U. S. Pat. No. 2,628,942.

Hereinbefore and hereinafter the term normal when referring to the saltof the alkenylsuccinimide denotes the ratio of the number of equivalentsof metal moiety to the number of equivalents of alkenylsuccinimidemoiety is about 1 and the term overbased when utilized in connectionwith the alkenylsuccinimide salts denotes the ratio of the number ofequivalents of metal moiety to the number of equivalents ofalkenylsuccinimide moiety is greater than about 1.

Although the prior normal metal alkenylsuccinimide as represented in U.S. Pat. No. 2,628,942 are satisfactory as crank-case dispersants, thereis a need due to the burden placed by auto emission control devices oncrankcase oils to also incorporate anticorrosive properties in such typeadditives.

SUMMARY OF INVENTION N Ca yCaCO where R is alkenyl of from 30 to 300carbons and y is an integer of from about 0.1 to 18.

The overbased calcium salt additives are prepared by contactingalkenylsuccinimide characterized by the formula:

with CO blown calcium 2-alkoxyalkoxide characterized by the formula:

11 cu ocmt:R200a.)...(ocociaciaocim where R is H, CH and/or C 11 x is aninteger of from about 0.5 to 1.5 and water initially utilizing an imideto CO blown calcium reagent to water mole ratio of between aboutl:0.5:0.l and l:9.5:l2 at a temperature between about 50 and 180C.,normally for a period of between about 1 and 3 hours. Under preferredconditions, the reaction is conducted under conditions of agitation andin the presence of an inert liquid diluent. The inert diluent whenemployed advantageously constitutes between about 10 and 50 vol. of thereaction mixture.

At the end of the reaction period, the crude product is preferablystripped with inert gas blowing such as nitrogen blowing, preferablyunder reduced pressure, to remove volatile materials therefrom. Theresultant overbased products, normally in liquid form, are desirablyfiltered via standard means to remove any solid impurities therefrom.

One of the essential features in the manufacturing process is theemployment of the CO blown calcium reagent as defined. Substitution ofnormally considered overbasing equivalents such as calcium oxide,calcium hydroxide or calcium oxide and calcium hydroxide solutions inlower alkanol will produce the normal calcium salts ofalkenyl-succinimide as disclosed in U. S. Pat. No. 2,628,942 but not thedesired overbased calcium salts.

The alkenylsuccinimide reactants are prepared by standard means such asreacting the maleic anhydride with a polyalkene polymer of from 30 to300 carbons, e.g., containing three to five carbon atoms repeatinggroups, such as at an elevated temperature, e.g., 200 to 300C. and thensubsequently passing ammonia through the resultant solution at atemperature between about and 250C. to form the alkenylsuccinimide asheretofore defined.

Specific examples of the succinimide reactant characterized by theformula:

are where R is polyisobutene of an average molecular weight of about500, R is polyisobutylene of an average molecular weight of about 800, Ris polyisobutene of an average molecular weight of about 1200, R ispolypropylene of an average molecular weight of about 1500, R ispolypentylene of an average molecular weight of about 2000 and R ispolybutene of an average molecular weight of about 3000.

The CO blown calcium-Z-alkoxyalkoxide reagent is prepared by thereaction of calcium carbide and 2- alkoxy-alkanol utilizing atemperature of between about 150 and 250F. and a mole ratio of alcoholfor calcium carbide of between about 3:1 and 100:1. The resultantmixture is then blown with carbon dioxide at a temperature between about50 and 150C. utilizing a calcium to carbon dioxide mole ratio of betweenabout 0.521 and 1.511 to form the CO blown reagent as precedinglydefined.

Examples of the calcium reagent characterized by the formula:

are where x is 0.5, x is l, x is 1.2 and x is 1.5 where R isrespectively H, CH C H Examples of the solvent suitable in themanufacture of the overbased calcium additive are benzene, toluene andother alkyl substituted liquid aromatic hydrocarbons; hydrocarbonlubricating oil of an SUS viscosity of between about 50 and 500 at100F.; alkanes such as heptane, isooctane, etc. as well as saturatedcyclic and alicyclic hydrocarbon solvents such as cyclohexane,methylcyclohexane, etc. When lubricating oils are employed, a lube oilconcentrate of overbased calcium succinimide is formed as the finalproduct. Volatile substances such as benzene, toluene and cyclohexaneare removed during stripping.

Examples of the overbased calcium salt product of the inventioncharacterized by the formula:

N Ca caco.

In the formulation of the lubricant composition of the invention,suitable base oils include a wide variety of hydrocarbon lubricatingoils such as naphthetic base, paraffinic base and mixed base mineraloils or other hydrocarbon lubricants, e.g., lubricating oil derived fromcoal products and synthetic hydrocarbon oils, e.g., alkylene polymerssuch as polypropylene, polyisobutylene of a molecular weight of betweenabout 250 and 2500. Advantageously, the lubricating oils having an SUSviscosity at F. between about 50 and 2000 are employed. The overbasedcalcium additives are incorporated in the base oils in an amount ofbetween about 0.5 and 20 wt. preferably between about 0.5 and 5.0 wt. Inthe finished lubricating oil compositions other additives may beincluded. These other additives may be any of the standard suitable pourdepressors, supplementary sludge dispersants, antioxidants, silvercorrosion inhibitors, viscosity index improvers and friction modifiers.Exactly what other additives are included in the finished oilcompositions and particular amounts thereof will, of course, depend onthe particular use and conditions desired for the finished oil products.

The following examples further illustrate the prod uct, method ofproducing and lubricant compositions thereof but are not to be construedas limitations thereof.

EXAMPLE I This example illustrates the preparation of thealkenylsuccinimide reactant.

Into 5280 grams (2.0 mole) of polyisobutene (1200 m.w.) succinicanhydride dissolved in polyisobutene (1200 m.w.), heated to 100C. therewas introduced at a rate of 500 mls./min. ammonia for 1 hour, then at C.for 0.5 hour and at C. for 0.5 hour. The resultant ammonia treatedreaction mixture was then flushed with nitrogen for 15 minutes andfiltered through diatomaceous earth. Approximately 5000 grams of productwere recovered and analysis found it to contain 0.56 wt. nitrogen. Itwas identified as polyisobutene (1200 m.w.) succinimide characterized bythe formula:

where R is polyisobutene of an average molecular weight of about 1200.

EXAMPLE II duced CO at a rate of 11 lbs. per hour for 1.5 hours 4 at 258F. At the end of the reaction period the resultant product was filteredthrough diatomaceous earth and was identified as CO blown calcium2-methoxyethoxide characterized by the formula:

where x is 1 and analyzed 8.0 wt. Ca.

EXAMPLE III This example illustrates the preparation of an overbasedcalcium alkenylsuccinimide species.

To 259 grams (0.10 mole) of polyisobutene (1200 m.w.) succinimidesolution of the type prepared in Example I dissolved in 100 mls. oftoluene there was added 100 grams of CO blown calcium 2- methoxyethoxideof the type prepared in Example II and 3.3 mls. (0.15 mole 25 percentmole excess) water. The resultant mixture was stirred 1 hour at 100C.,stripped with nitrogen blowing to a temperature of 180C., then strippedusing a water aspirator (20 mm Hg) to 180C. and filtered throughdiatomaceous earth. The recovered liquid product weighed 262 grams andwas characterized by the formula:

where R is polyisobutene (1200 m.w.) and y is 3.0. Analysis of theproduct found a nitrogen content of 0.49 wt. (0.51 calc.) and a calciumcontent of 3.0 wt. (2.91 calc.).

EXAMPLE IV This example further illustrates the preparation of theoverbased calcium alkenylsuccinimide and the lube oil concentrate.

To 1000 grams of naphthenic oil having an SUS viscosity of 100 at 100F.there was added 259 grams (0.102 mole) of polyisobutene (1200 m.w.)succinimide solution as prepared in Example I. The resultant mixture washeated to 90C. and there was added 50 mls. of CO blown calciumZ-methoxyethoxide as prepared in Example 11. The resultant mixture washeated to 90C. for a period of 15 minutes whereupon an additional 50mls. of calcium reagent and 5 mls. of water were added. The temperaturewas again held at 90C. for 15 minutes. The calcium reagent and wateradditions and stirring period were repeated four more times and theresultant mixture was stripped with nitrogen blowing to 180C, filteredthrough diatomaceous earth and 60 grams of solid product were removed onthe filter. A total of 250 grams of calcium reagent and 18 grams ofwater are employed. The resultant liquid filtrate was identified as alube oil solution containing about 15 wt. of an overbased calciumpolybutene 1200 m.w.) succinimide characterized by the formula:

where R is polyisobutene of an average molecular weight of about 1200, yis 4. The product was analyzed and found to contain 0.10 wt. nitrogen(calc. 0.094) and 0.7 wt. calcium (calc. 0.9).

EXAMPLE V This example further illustrates the preparation 'of thecalcium overbased alkenylsuccinimide.

To 368 grams (0.1 mole) of polyisobutene (1200 m.w.) succinimidesolution heated to C. there was added 24.4 grams of CO blown calcium 2-methoxyethoxide of the type prepared in Example 11 over a 5 minuteperiod and the resultant mixture was stirred 5 minutes, stripped withnitrogen to 150C., cooled to C. Then 24.5 grams of calcium reagent ofthe type perpared in Example II simultaneously with 5 mls. of water and25 mls. of Z-methoxyethanol were added over 5 minutes and theaforedescribed stirring, stripping and cooling sequence were repeateduntil a total of 146 grams of calcium reagent, 25 mls. of water and mls.of 2-methoxy-ethanol were added. The resultant mixture was then strippedto 180C. with CO blowing (1000 mls./min.) and filtered throughdiatomaceous earth. The resultant product filtrate was recovered in anamount of 258 grams and was identified as characterized by the formula:

where R is polyisobutene in an average molecular weight of about 1200and y is 6. Further analysis of the product found it to contain 2.8 wt.calcium (3.95 calc.) and 0.29 wt. nitrogen (0.35 calc.).

EXAMPLE VI This example illustrates the preparation of overbased calciumpolyisobutene succinimide.

Three hundred sixty eight grams (0.10 mole) of polyisobutene (1200 m.w.)succinimide were heated to 90C. and there were added 24.4 grams of COblown calcium 2-methoxyethoxide of the type produced in Example 11. Theresultant mixture was stirred 10 minutes, stripped to 150C. with carbondioxide blowing (500 mls./min.) and the temperature reduced to 90C.There was then added additional 24.4 mls. of calcium reagent of ExampleII and 5 mls. water and 25 mls. of 2-methoxyethanol simultaneously overa 5 minute period. The resultant mixture was stripped and cooled asbefore and repeated until all the calcium reagent and water solution wasemployed and the resultant mixture was stripped to C. with CO blowingand the resultant mixture was filtered through diatomaceous earth withthe recovery of 288 grams of product. A total of 97.6 grams of calciumreagent (0.4 equivalents) were utilized. The product was analyzed anddetermined to be overbased calcium polyisobutene (1200 m.w.) succinimidecharacterized by the formula:

wherein R is polyisobutene of an average molecular 7 weight of about1200 and y is 2.5. Analysis of the mixture found 1.4 wt. Ca, 0.28 wt. N.

EXAMPLE VII This comparative example illustrates the importance ofemploying the method of the invention to prepare the overbased calciumalkenylsuccinimide.

To 269 grams of polyisobutene (1200 m.w.) succinimide (0.10 mole)solution there was charged 14 rams calcium oxide (0.25 mole), 100 gramsethylene glycol (1.6 mole), 100 mls. toluene and 4.5 mls. water (0.25mole 25 mole excess). The resultant mixture was refluxed at about 1 C.for 3 hours with CO blowing (500 mls./min.) then stripped to 100C.utilizing a water aspirator mm Hg). Eighty five mls. of toluene and 864grams of polar material were stripped out. The product was unfilterableand of a grease-like quality. No useful lubricating oil additive asobtained by this process.

The foregoing procedure was repeated utilizing 233 grams ofpolyisobutene (1200 m.w.) succinimide, 14 grams calcium oxide, 100 mls.ethylene glycol, 100 mls. toluene, 4.5 mls. water and 149 grams ofnaphthenic mineral oil having an SUS viscosity at 100F. of 100. Theresultant mixture was refluxed for 3 hours at about 120C. whilesimultaneously passing 700 mls./min. CO therethrough. The resultantmixture was stripped to 180C. utilizing a water aspirator (20 mm Hg).The resultant product would not filter and analysis indicated that nooverbased product was formed.

EXAMPLE VIII This example illustrates the lubricant compositions of theinvention contemplated herein and also illustrates the function of theoverbased calcium alkenylsuccinimide as an effective dispersant inlubricating oils.

The test procedure employed comprises introducing into a bottle the testlubricating oil compositions, titanium oxide (6 wt. in oil and engineblowby. The bottle was agitated at an elevated temperature for a periodof time and a portion of the bottle contents was centrifuged. Uponcentrifuging, three phases are formed, i.e., a top clear oil phase, amiddle dirty oil phase in which sludge remains dispersed and a bottomsediment phase. The clear oil and sediment depth are measured inmillimeters and recorded as the first cycle. For the second andsubsequent cycles to the sample remaining in the bottle from the firstcycle portions of the following materials were added in the orderlisted: titanium oxide (6 wt. in oil and engine blowby and the procedureof the first cycle is repeated. The cycles are continued until thecentrifugal oil is clear and completely free of sediment. The greaterthe depth of sediment and clear oil in the centrifuged tube the less thedispersant capacity of the test oil composition.

The base oil composition employed on the foregoing test to which theoverbased calcium alkenylsuccinimide is added is of the followingcomposition:

TABLE I Description Wt. Paraffinic Oil 89 (-140 SUS at 100F.) CO2 blown1:1 overbased barium alkylphenolate Zinc dialkyldithiophos;

phate 6 CO2 blown 1:1 overbased barium sulfonate 750 ppm Siliconepolymer antifoamant Copolymers of butyl to 5 stearyl methacrylate (3500SUS at 210F.)

TABLE II Overbased Base Ca Run Oil Additive Bench Sludge Test N0. Comp.Wt. Cycle 1 2 3 4 A 100 0 Clear 41 3s Sediment 9 2 B 96.6 3.4 Clear 2 36 Sediment 4 9 8 1 1 *Product Ex. Ill

EXAMPLE IX This example illustrates the rust inhibiting properties oflubricant compositions containing the overbased calciumalkenylsuccinimide and also illustrates lubricant compositionscontaining said succinimide.

The rust test employed is a low temperature engine procedure whichcomprises lubricating a 1964 289 CID V-8 engine. The engine is run underthe following test conditions.

TABLE III Description Value Duration, hrs. 45 Speed, rpm 1500 Load, BHP28 Fuel pressure, psi 4.5 Fuel/air ratio 0.085 Crankcase Ventilation,"F. Jacket Out 90 Oil Gallery 1 10 Rocker Arm Covers 60 Intake Air 1 10At the end of the test period of the various engine runs the externaland internal area of the valve. lifters and push rods were inspected. Arating of 10 represented no rusting and a rating of zero indicated heavyrusting of the entire surfaces. Three compositions were subjected tothis test. These formulations (Oils C, D and E) all consisted of thesame base composition, namely, a paraffinic lubricating oil of -130 SUSviscosity at F. containing a zinc dialkyl dithiophosphate, supplementaryashless dispersant and methacrylate VI improver. Additionally, in Oil Cthere was also present an overbased succinimide of the type described inExample III but R was at 400 m.w. polybutene. In Oil D a comparativerust preventive compound, calcium overbased P S -polybutene (400 m.w.),was present.

The calcium level in both Oils C and D was 0.175 wt. tive. Oil E wassaid base composition per se. 5. A lubricant composition according toclaim 3 The test results in this rust test are as follows: wherein R ispolyisobutene of an average molecular weight of about I200. TABLE IV 56. A method of producing overbased calcium alke Additive T t 0 wt. CaHilts mama] Exlem nyl succmimide characterized by the formula. c 0.17545 3.9 8.7 D 0.175 45 3.6 8.2 E 0 21 4.5 7.8

I The above demonstrates the utility of overbased al- I N Ca yCaCOkenylsuccinimide products to prevent rusting in auto- H motive engines.2

We claim: 15 O 2 1. An overbased calcium alkenylsuccinimidecharacterized by the formula:

where R is alkenyl of from 30 to 300 carbons and y is an integer of fromabout 0.] to 18 comprising contacting an alkenylsuccinimide of theformula:

H O I R NH l H- C-C where R is alkenyl of from to 300 carbons and y is 0an integer of from 0.1 to 18. 0

2. A compound in accordance with claim 1 wherein R is polyisobutene ofan average molecular weight of about 1200.

3. A lubricating oil composition comprising a major 0 amount of arefined mineral lubricating oil and a small 5 amount sufficient toimprove detergency and rust inhibition thereof of an overbased calciumalkenylsuccinimide characterized by the formula:

where R is as heretofore defined with a C0 blown calcium methoxyethoxidecharacterized by the formula:

where R is H, CH and/or C H where x is between about 0.5 and 1.5 in thepresence of water at a temperature between about 50 and 180C. utilizinga mole ratio of said alkenyl-succinimide to calcium reagent to l saidwater to between about l:0.5:0.l and l:9.5:l2.

7. A method in accordance with claim 6 where R is H. I Ca ycaco" 8. Amethod in accordance with claim 7 where said H C-C contacting isconducted in the presence of inert liquid diluent in an amount ofbetween about 10 and vol.

% of the reaction mixture.

9. A method in accordance with claim 8 wherein said where R is alkenylof from 30 to 300 carbons and y i 50 solvent is toluene, hydrocarbonmineral lubricating oil, an integer of from 0.1 to 18. or2-rnethoxyethanol and said R is polyisobutene of an 4. A lubricantcomposition according to claim 3 conaverage molecular weight of about1200. taining between about 0.5 and 10 wt. of said addi- 0mm CERTIFICATE9F CQRRECTION Patent No. 3,7 h53 at dt b r 9, 1973 WALTER w. HELLMUTHand ELMER E. SCHALLENBERG ro-xoso Inventor) It in certified the: errorapmm'em the above fldontifiad patent and that said Letters Patent ewehereby estimated as shown below:

' Col. 1, line 1%, "exhuast" should read --exhaust-.

Col. 1, line 41, "crank-case" should read "crankcase".-

Col. 2, line 55, CH3 CH3 should read -CH CH -CH C CH Q CH 3 3 H C CH C tn Col. 5, llne 6, 'Ca (OCR CR OCR (O C QCR CR OCB should read UNITEDSTATES PATENT OFFICE Page 2 CERTIFICATE OF CORRECTION Patent N BKZ LB Jt d October J, l

inventor) Walter W. Hellmuth and Elmer E Schallenimrg It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

601. Taole II, lines ZLr-ZS "Over" in the first column (line 2L;,) ofTable II should be located directl; above "based" (line 25), 3rd columnof Table II.

Signed. and sealed this 30th day" of April 19714..

(SEAL) Atte st 2 EDE IARD VELETCIERJR Q C MARSHALL DANN AttestingOfficer Commissioner of Patents FORM PC4050 (10-69) USCOMM-DC wan-Pee WU.5. GOVERNMENT PRINTING OFFICE 1 19 59 0-366-33L

2. A compound in accordance with claim 1 wherein R'' is polyisobutene of an average molecular weight of about
 1200. 3. A lubricating oil composition comprising a major amount of a refined mineral lubricating oil and a small amount sufficient to improve detergency and rust inhibition thereof of an overbased calcium alkenylsuccinimide characterized by the formula:
 4. A lubricant composition according to claim 3 containing between about 0.5 and 10 wt. % of said additive.
 5. A lubricant composition according to claim 3 wherein R'' is polyisobutene of an average molecular weight of about
 1200. 6. A method of producing overbased calcium alkenyl-succinimide characterized by the formula:
 7. A method in accordance with claim 6 where R is H.
 8. A method in accordance with claim 7 where said contacting is conducted in the presence of inert liquid diluent in an amount of between about 10 and 50 vol. % of the reaction mixture.
 9. A method in accordance with claim 8 wherein said solvent is toluene, hydrocarbon mineral lubricating oil, or 2-methoxyethanol and said R'' is polyisobutene of an average molecular weight of about
 1200. 